Blasphemy: http://members.shaw.ca/superion/Desecration.html
Archgoat: Blasphemous Underground, hoodies and shierts just out, or out this month
Blasphemophagher - nwn distro? if sould out, then ask band
Beherit - I think bootleg shirts can be found in maaaaany distros

Neseblod Records had a couple of old Rotting Christ shirts last time I looked. I was very tempted, but the guy who runs it drives for a big price tag, and I couldn't justify spending that much on a shirt at the moment.